Sep 21, 2012 - 4:00pm

As the New York Times reported September 19th, scientists at the US National Snow and Ice Data Center recently announced on that Arctic sea-ice extent had fallen to 3.41 million square kilometres—the lowest summer minimum extent since satellite observations began in 1979.

Summer sea-ice in the Arctic has been has been retreating more or less towards the North Pole for three decades as ocean and air temperatures have risen.

In September 2007, the ice hit a new record of 4.17 million square kilometres. Importantly, even though the northern summer of 2012 has not been as warm as that of 2007, thinning of the sea ice is making it more prone to melting in summer. Indeed, while a recent storm churned up ice, propelling the Arctic towards this new record low, sea-ice thinning renders it more vulnerable to such extreme events.

The new record minimum is nearly 800,000 square kilometres less, or an area not far off that of New South Wales.